1. Field of the Invention
The present invention relates to a wiring board adapted for electronic component (such as IC and LSI chip) inspection of conductive properties, operability or defects, and to a method of manufacturing the same. More particularly, the present invention relates to an electronic component-inspection wiring board (probe card-wiring board) made of ceramic layers that are co-fired with metallic wiring layers and made from the same ceramic material. Further, the present invention relates to a method of manufacturing the electronic component-inspection wiring board.
2. Description of the Related Art
For inspection of conductive properties, operability, or defects of a microelectronic component such as an IC or LSI chip, a probe card has been proposed (see, for example, Patent Document 1). The probe card generally includes a wiring board comprising a base substrate composed of ceramic layers through which via-conductors are formed for passing inspection signals; and organic insulating layers that are formed on the base substrates; wherein thin film wiring layers and contact-pads are formed in or on the organic insulating layers so that the electronic component can directly or indirectly make electrical contact with the pads so as to be inspected by the inspection signals transmitted through the contact pads.
Patent Document 1: Japanese Patent Application Laid-Open No. 2006-275714 (pages 1-6, FIGS. 1-5)
3. Problem to be Solved by the Invention
In order to accurately collect inspection information from a microelectronic component, a rigid probe card-wiring board (or rigid electronic component-inspection wiring board) is necessarily required. Since a conventional electronic component-inspection wiring board comprises an organic insulating layer with a contact-pad formed thereon, the rigidity thereof is not sufficient. A probe card-wiring board having improved rigidity may be obtained if the organic layers formed on the base ceramic substrate are replaced with ceramic layers. However, if a higher density per unit volume is required of conductors wired in the ceramic layers (first ceramic laminate) than in the base ceramic substrate (second ceramic laminate), it will be very difficult to obtain a probe card-wiring board free of positional misalignment of the pads and the via-conductors, especially at the interface between the two ceramic laminates. If the first and second laminates are cofired at the same time, the position of a pad located on the uppermost layer or a via conductor exposed at the uppermost layer of the ceramic wiring board would deviate from their desired respective positions. As a result, inspection information of the microelectronic component neither can be accurately collected nor analyzed.